4. ..Ae8+!
The "deviation". You have to move the White Bishop from the a6 key, to liberate the 'a' pawn.[Even here, the engines insist with Bh5: 4. ..Bh5?! 5.Kb7 e2 6.Bxe2 Bxe2 7.Kxa7=]5.Kb7 Bb5! 6.Bxb5 a5 7.h5 a4 0-1. The Bishop can not stop both passed pawns 'a' and 'e'.
Notice how the engines on the second and fourth move, are limited to consider the draw move Bh5.// // // // // // // // // //

Training - Light pieces endgames.

Training2 - Light pieces endgames.

This database contains ten endgames played among GM.
It are all light pieces endgames (Knight, Bishop + pawns).
The games are instructive examples of as to treat these positions.
I have select these games because it develop themes and typical strategies used by the GM when they plays these endgames types.
For the databse installation to follow the procedure explained for the game Fischer-Taimanov:page